A kind of preparation method of elbow tee pipe

Abstract

The invention discloses a method for preparing a bend t-branch pipe. The method includes the steps that a round pipe blank is cut at first according to the length required by a forming part; then an internal high-pressure forming technology is adopted to prepare the round pipe blank into a T-shaped straight tee directly; the T-shaped straight tee is bent, namely a straight tee part which has already been formed is put into a mold cavity, a mold is closed, and then the straight tee part is formed into a preforming part required; the preforming part is subjected to annealing treatment, and machining stress is removed; and a bent t-branch pipe is put into an internal high-pressure mold for conducting internal high-pressure forming after annealing, and the outer surface of the part is attached to the mold cavity to obtain a final product. The method for preparing the bend t-branch pipe has the advantages that the thickness reduction degree at the bent position is low and the using requirements can be met.

Description

technical field [0001] The invention relates to the technical field of bulging of bent pipe fittings, in particular to a method for preparing a bent pipe tee. Background technique [0002] In the engine exhaust manifold of automobiles, due to the complex structure, tailor welding and casting processes were often used in the past. With the rise of hydroforming technology, a large number of directly formed tees have been put into use. Through special internal high-pressure equipment, the pipe can be directly formed into a three-way pipe. In actual production, in addition to the straight tee, there is also an elbow tee. The straight tee can be refilled in the axial direction at the same time. The molding process is stable, and the thickness of the formed tee is thicker. As for the elbow tee, the specific technological process is: blanking——bending—annealing—first forming—annealing—second forming; At that time, the wall thickness of the bending part has been reduced by about ...

AI Technical Summary

Problems solved by technology

As for the elbow tee, the specific process flow is: blanking - bending - annealing - first forming - annealing - second forming; At that time, the wall thickness of the bending part has been reduced by about 20% due to deformation (stretching). At this time, the first forming of the tee is performed, and the thinning position is easily affected by the length of both ends. When forming, it is bent The inner corner of the bending part is easy to wrinkle, and the wall thickness of the formed tee pipe is often very thin, resulting in a thickness reduction of 40% to 50% in the final bending part, so it cannot meet the use requirements and cause a great safety hazard

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